Indicators of properties and feature of behaviour of samples of polyethylene films (LDPE) in the thickness 40ч150 a micron and packages on their basis in the thickness 100ч1200 a micron are studied at a lateral contraction by a passing wave with speeds of deformation to 3500 s-1. The device is created and the technique of dynamic tests of thin sheet samples under the wave scheme of a compound core of Gopkinsona is developed. For registration of wave processes in the sample and wave guides are used tensoresistor and the piezoelectric measuring contours co-ordinated under the developed scheme of control of signals from gauges. The data about a kinetics of dynamic deformations, pressure and speeds of deformations in sheet samples depending on a thickness of films and structure of package systems from them is obtained. Test data testify to the considerable difference of levels of complex moduli of elasticity at a lateral contraction, investigated samples, from elastic moduli of the same films at dead loads. The considerable influence of a thickness of a film on an elastic modulus on the investigated schemes of wave compression is established.